Automatic pressure controlled switch



Sept. 18, 1956 c. D. sPRAcHER AUTOMATIC PRESSURE CONTROLLED SWITCH FiledNov. 3, 1952 vr til I #rmi/Vix United States Patent O 2,763,747AUTOMATIC PRESSURE CONTROLLED SWITCH Clifford D. Spracher, Downey,Calif. Application November 3, 1952, Serial No. 318,372 2 Claims. (Cl.200-83) This invention relates to a novel automatic pressure controlledswitch, particularly one which is used in connection with an internalcombustion engine, this engine having a pressure oil system. Thepressure of the oil system of the engine actuates the diaphragm of theswitch so as to shut off the engine whenever the pressure of the oilsystem is reduced to a certain minimum.

An object of my invention is to provide a novel automatic pressurecontrolled switch which is applicable to engines having either magnetoor a battery type ignition system.

Another object of my invention is to provide a novel automatic pressurecontrolled switch including a sensitive switch commonly termed amicro-switch, this switch being actuated by the rise or fall of thepressure of the oil system of the engine.

A feature of my invention is to provide a novel automatic pressurecontrolled switch which can be varied as to its sensitivity byadjustment of a spring within the switch.

Other objects, advantages and features of invention may appear from theaccompanying drawing, the subjoined detailed description and theappended claims.

In the drawing:

Figure 1 is a longitudinal sectional view of my switch showing theswitch in closed position.

Figure 2 is a sectional view taken on line 2-2 ure 1.

Figure 3 is a fragmentary longitudinal sectional View similar to Figure1 but showing the switch in open position.

Referring more particularly to the drawing, the numeral 1 indicates apressure housing which includes a chamber' 2. A diaphragm 3 extendstransversely across the chamber 2 and is mounted within the housing 1,substantially as shown. An intake port 4 extends into the chamber 2 andthis port is connected to the pressure oil system of the engine so thatpressure may be exerted by the oil of the engine on one side of thediaphragm 3. A rod 5 is secured at one end to the diaphragm 3 and thisrod extends through a box 6 and is journalled in one wall of the box.

A spring 7 within the housing 1 bears against the diaphragm 3, tendingto tlex the diaphragm towards the left, as viewed in Figure 1. A groundterminal 8 extends into the housing 1 and includes a ground button 9which is engaged by the terminal 10 in one position of the rod 5. If theengine is provided with a magneto, the ground wire from that magneto canbe attached to the end of the rod 5, and also the terminal 8 can begrounded through an appropriate wire. When the contact 10 engages thebutton 9, the magneto of the engine would, therefore, be grounded andthe engine would be stopped. This would occur when the oil pressure ofthe engine would drop to permit the spring 7 to press the contact 10against the button 9. A spring nger 11 is attached to the outer end ofthe rod 5 and can be placed in the notch 12, thus pulling the contact 10away from the button 9, which is necessary of Figwhen the engine isbeing started. As soon as the engine starts the oil pressure will ex thediaphragm 3 to the right, as shown in Figure 3, and will thus hold thecontacts 9 and 10 apart.

The box 6 is attached to the housing 1 in a suitable manner, such as bymeans of the bolts 13. A sensitive switch (termed a micro-switch) 14 isixedly mounted within the box 6. A nger 15 is tixedly secured to the rod5 and this finger extends over and engages the actuating pin 16 of thesensitive switch. It will thus be evident that as the rod 5 moves underthe urge of the diaphragm 3 that the switch 14 will be opened andclosed, depending upon the position of the finger 15. A binding post 17on the box 6 is connected to the switch 14 and this binding, post servesas the common electrical terminal. An electrical lead is attached to thepost 17 as shown. A second binding post 18 is also mounted on the box 6and this binding post is so connected to the sensitive switch 14 thatcurrent will be transmitted to this binding post in the normally openposition of the switch. A third binding post 19 on the box 6 isconnected to the switch 14 so as to conduct current thereto in thenormally closed position of the switch. Thus it will be evident thatwhen the switch is open, current will be fed to the binding post 18, andwhen the switch is closed, current will be fed to the binding post 19.

When the oil pressure of the engine drops, the diaphragm 3 will ex tothe left, as shown in Figure 1, and the finger 15 will then close theswitch 14 by engaging the pin 16. In this position of the parts, currentis fed to the binding post i9 and an alarm or a light may be attached tothis binding post to indicate that the engine has stopped. Similarly,when the engine is running, oil pressure tlexes the diaphragm 3 to theright, as shown in Figure 3.

The switch 14 is now open since the linger 15 moves away from the pin16. Therefore, current is fed to the binding post 18 and again suitableequipment can be attached to this binding post, or the ignition systemof the engine may be attached to this post if a battery ignition systemis used. It is sometimes necessary that the rod 5 shall move quicklywith respect to any change in the oil pressure ot' the engine. To aidand assist the spring 7 in controlling the movement of the rod 5, Iprovide a toggle plate 20 which is pivotally mounted at 21 in the box 6.The toggle plate 20 is formed with a notch 22 into which one end of thelinger 15 extends.

A spring 23 is hooked at one end to a horn 24 of the toggle plate 20.The spring 23 may also be hooked over the opposite horn 25 of the toggleplate, depending on whether it is desired to oppose or aid the spring 7.The lower end of the spring 23 is attached to a bolt 26 which threadsthrough the box 6, and by adjusting the length of this bolt within thebox 6 it is possible to vary the tension of the Spring 23. When thespring 23 is hooked to the horn 24, it opposes the spring 7, tending toopen the terminals 9 and 10. When the spring 23 is hooked over the horn25 it aids the spring 7 and tending to close the contacts 9 and 10.

In operation and starting rst with the parts arranged as in Figure 1,the spring 7 is flexing the diaphragm 3 so as to press the contact 10against the button 9, and this makes contact to the ground wire from thebinding post 8, thus grounding the engine magneto, the ground wire ofwhich is attached to the rod 5. This is the position of parts when theoil pressure of the engine is either zero or very low. As soon as theengine starts, the oil pressure entering the port 4 will flex thediaphragm 3 to the right, as shown in Figure 3. This breaks the contacts9 and 10 and the engine (if it has a magneto) can operate. The sensitiveswitch 14 is being simultaneously operated and in the position of theparts shown in Fig ure -1 the switch 14 is closed, since the "linger 1Sis depressing the pin 16. The binding post 19 has current owing to it inthis position and suitable equipment can be attached to this bindingpost. When the engine is operatingV and the parts are as shown inlFigure 3 the switch 1'4 is open and current flows rto the binding post18; which again can be used to Control electrical apparatus or theignition system of the engine itself, if a battery system is used. Thetension spring 23 Vcan be moved from one side ofthe toggle plate to theother, depending onwhether it is `desired to increase or decrease theaction of the spring `7. Also the tension of the spring 23 can bewadjusted by rotating the bolt 26j.

Having described my invention, 4I claim:

1. An 'automatic pressure controlled s witchcornprising a housing, aViiexible diaphragm Vextending transversely across the housing, saidhousing having a duid pressure intake ,por-ttherein,v said port'extending to one side of the diaphragm, an electrical terminal extendinginto the housing, a rod, one end of said rod being iixedly secured tothe diaphragm, said rod projecting through the diaphragm, and' theprojecting end thereof being engageable with said terminal, a lingermounted on the rod', a box mounted on the housing, a sensitive switchmounted in the box, an actuating pin rising from the switch, said fingerengaging the pin to actuate the switch on movement of the rod, and aspring in the housing bearing against said diaphragm to urge saiddiaphragm in a direction to contact the rod with said terminal, a toggleplate pivotally mounted in the box, said toggle plate having a notchtherein, one end of said finger projecting into the notch, and a springin the box, one end of said spring being attached to the toggle plate.

2, An automatic pressure controlled switch comprising a housing, aiiexble diaphragm extending transversely across the-housing, saidhousing having a tluid pressure intake port therein, said port extendingto one side ofr the diaphragm, an electrical terminal extendinginto thehousing, `a rod, one end of said rod being ixedly secured to thediaphragm, said rod projecting throughV the diaphragm, and theprojecting end thereof being engageable with said terminal, a fingermounted on the rod, a box mounted on the housing, a sensitive switchmounted in the box, an actuating pin rising from the switch, said:linger engaging the pin to actuate the switch on movement of the rod,and a spring in the housing bearing against said diaphragm to urge saiddiaphragm in a direction to ContactY the rod with said terminal, atoggle plate, pivotally mounted in the box, said toggle plate having anotch therein, one end of said ringerl projectingv into Vthe notch, anda spring in the box, one end -of said springl being attached to thetoggle plate, a bolt threaded through the wall. of the box, saidl springbeing secured to the bolt at one end thereof, binding posts mounted inthe box, and electrical leads extending from the binding posts to thesensitive switch.

.References Cited in the tileV of this patent UNlTED STATES PATENTS690,515 Comstock Ian. 7, 1902 956,679 Champ et al May 3, 1910 1,252,560Evans Ian. 8, 1918 2,007,409 Schweitzer July 9, 1935 2,028,196 Du BrieJan. 21, 1936 2,033,417 Dezotell Mar. 10, 1936 l2,131,264 Benjamin Sept.27, 1938' 2,194,533 Van Dyke Mar. 26, l1940 21,358,732 Otto Sept. 19,1944 2,360,723 Schaefer Qct 1'7', 1944 2,418,536' Wood Apr. 8, 19472,506,208 Gibson May 2, 1950 FOREIGN PATENTS 183,678 YGreatritain Aug.3,. 1922 560,775 France July 18, 19123 690,858 Germany May 9, )1940l

